When carrying out any sort of construction work that involves an excavation, it is essential to conduct a thorough survey of the site before commencing work.

Certainly, the first thing to do is to obtain plans or other suitable information about all underground services in the area in which you are going to work. That means that you need to contact the owners and operators wherever possible, and also remember that some services may have more than one owner or operator.

There are also certain services that you can contact which can often provide information, such as Linesearch BeforeUdig. The more information you can obtain, the better. If it is not possible to obtain detailed information, for example, if carrying out emergency work, it is vital that the work is carried out on the basis that there will be underground services in the area.

Most electrical services belong to the regional distribution network operator, but some electrical cables may belong to the MOD, the highways authority, street lighting authority, National Grid, a railway operator, or other companies.

Most of the gas pipes are owned by the public gas transporter, but some new developments are supplied by independent gas transporters, and others may be fed by bulk stored LPG suppliers.

There may be other services on or around hospitals, universities, MOD sites, research parks, petrochemical, and other sites, in which case it is necessary to contact the site owners.

It is also necessary to realise that the plans and services that you obtain details of may not be accurate. There can be many reasons for this, but unfortunately it is a fact. All plans should be obtained at the design stage so that the position of underground services can be taken into consideration.

It is essential to note the following from the HSE guide HSG47:

“Plans alone are not sufficient to identify and locate services before starting work. They provide basic information on which to base a thorough site survey before work begins”.

HSG47 also goes on to note that “Time spent on a survey at this stage can save significant costs and delays to the work by allowing for the avoidance of damage to underground assets and efficient programming of the work”.

More importantly, it can help to avoid serious injury to the workers engaged in the actual excavation. HSG47 quotes an incident where a self-employed contractor was burnt when using an electrical breaker to break up some concrete when he hit a 415volt electric cable. The cable had been protected by a conduit and the location was known. The client failed to tell the contractor before he started work, and the contractor did not ask.

All operatives who are to carry out site surveys for underground services should receive thorough training in the skills required to undertake such work and in the use of the tools that are needed. At Sygma Solutions, we have a combined experience of over 100 years in the detection and location of underground services, together with experience of the manufacture of the CAT and Genny. We also service and calibrate Mala GPR equipment and we have such equipment for hire for contractors who wish to undertake their own surveys.

Our training courses in the use of the equipment for location and identification of underground services are recognised by the CITB and The Survey Association. They cover the use of the CAT and Genny in all their different modes, and include a course on the use of the Metrotech Vivax VLoc Pro. This is an advanced tool that uses dual core processing and collocated antennae in order to help operators locate and detect underground services.

Our Vivax training course in the classroom – or online – begins with an overview of the necessity for locating and identifying underground services and covers the HSG47 guidelines. Operative will also learn how to interpret buried service STATS plans which give an indication of the routes of underground services. Our Vivax training also shows operatives the various features and functions of the VLoc Pro including transmitter configuration and how to use it in the different modes.

Classroom work is then followed by further training on site so that every operative understands how to use the tools in a practical situation.